A fix is available
APAR status
Closed as new function.
Error description
REORG INDEX improvements
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * All Db2 12 for z/OS users of REORG INDEX * * utility * **************************************************************** * PROBLEM DESCRIPTION: * * New function and performance * * improvement for the REORG INDEX * * utility with the new NOSYSUT1 keyword * **************************************************************** * RECOMMENDATION: * **************************************************************** This APAR introduces a new keyword option, NOSYSUT1, to the REORG INDEX utility. When REORG INDEX SHRLEVEL REFERENCE or CHANGE is specified with the new NOSYSUT1 keyword option, the utility will behave as follows: 1. The default SYSUT1 or work data set provided by the WORKDDN keyword is no longer required or used. REORG INDEX would process keys in memory between unload and build processing without using a work data set. User can omit the specification of the SYSUT1/WORKDDN data set or leave them as is in the existing JCL or utility statement. 2. REORG INDEX will utilize parallel subtasking to perform the index key unload and build processing concurrently. The number of subtasks to be started is dependent on the index type being reorganized and available system resources, which REORG INDEX would determine the optimal degree of parallelism based on these criterias. --------------------------------------------------------------- REORG INDEX syntax diagram changes: https://www.ibm.com/docs/en/db2-for-zos/12?topic=index-syntax- options-reorg-control-statement >--REORG INDEX---... |--PARALLEL 0-------------| >--|------------|-----|-------------------------|--- |--NOSYSUT1--| |--PARALLEL num-subtasks--| NOSYSUT1 Specifies that REORG INDEX is not to use a work data set (default SYSUT1) to hold the unloaded index keys. The utility passes the unloaded keys in memory as input to the index build for this process. Avoiding usage of the work data set can improve performance. The NOSYSUT1 option is ignored if SHRLEVEL NONE is specified or defaulted. If NOSYSUT1 is specified and an error occurs during index keys unload or build, you must perform a phase-restart of the utility from the beginning of the UNLOAD phase. This is only for SHRLEVEL REFERENCE since SHRLEVEL CHANGE is not restartable until the SWITCH phase. PARALLEL(num-subtasks) Specifies the maximum number of subtasks that are to be started in parallel to reorganize the index. If the PARALLEL keyword is omitted, the maximum number of subtasks is limited by the number of index or index partitions that are being reorganized. This keyword option is ignored if REORG INDEX cannot drive subtask parallelism for its internal processing. The value of num-subtasks must be an integer between 0 and 32767, inclusive. If the specified value for num-subtasks is greater than 32767, the REORG INDEX statement fails. If 0 or no value is specified for num-subtasks, the REORG INDEX utility uses the optimal number of parallel subtasks. If the specified value for num-subtasks is greater than the calculated optimal number, the REORG INDEX utility limits the number of parallel subtasks to the optimal number with applied constraints. The specified number of subtasks for PARALLEL always overrides the specification of the PARAMDEG_UTIL subsystem parameter, so PARALLEL can be smaller or larger than the value of PARAMDEG_UTIL. --------------------------------------------------------------- The following new message is added to support this REORG INDEX new function: https://www.ibm.com/docs/en/db2-for-zos/12?topic=messages- dsnu2909i DSNU2909I csect-name - INDEX OR INDEX PARTITIONS WILL BE PROCESSED IN PARALLEL, NUMBER OF TASKS=n Explanation The REORG INDEX utility is processing the target index or index partitions in parallel using one or more concurrent utility subtasks. The total number of index unload, build and statistics tasks started is n. System action Utility processing continues. Severity 0 (informational) Existing message DSNU700I is not changed, but explanation is modified to include the new REORG INDEX usage: DSNU700I csect-name nnnn INDEX ENTRIES UNLOADED FROM INDEX=iiii PARTITION=pppp Explanation The REORG utility or the UNLOAD phase of the CHECK utility unloaded nnnn records from the index named iiii and partition pppp. System action Processing continues. Severity 0 (informational) --------------------------------------------------------------- For ease of enablement, a new online changeable subsystem parameter is also introduced to enable the new REORG INDEX NOSYSUT1 behavior without specifying the new NOSYSUT1 keyword on the utility statement. REORG INDEX NOSYSUT1 (REORG_INDEX_NOSYSUT1 subsystem parameter) The REORG_INDEX_NOSYSUT1 subsystem parameter specifies whether the REORG INDEX SHRLEVEL REFERENCE or CHANGE utility should avoid using the SYSUT1 or work data set to hold the unloaded index keys. The utility passes the unloaded keys in memory as input to the index build for this process. Enablement of this option also allow REORG INDEX to utilize parallel subtasking to unload and to build the index keys in its internal processing. The following values are supported: NO REORG INDEX uses the SYSUT1 or specified work data set to hold the unloaded index key (default) YES REORG INDEX avoids using the SYSUT1 or specified work data set to hold the unloaded index keys, which also enables the utility to utilize parallel subtasking to unload and to build the index keys.
Problem conclusion
Temporary fix
Comments
Code has been modified to introduce the aforementioned new function to the REORG INDEX utility. ×**** AE21/07/27 FIX IN ERROR. SEE APAR PH39309 FOR DESCRIPTION
APAR Information
APAR number
PH25217
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
C10
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-05-08
Closed date
2021-05-19
Last modified date
2021-10-13
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI75477
Modules/Macros
DSNURBII DSNTIDXA DSNTINST DSNTIDXC DSNTIWIA DSNTIDXB DSNTIWMD DSNTIWIE DSNFUDRA DSNURFIT DSNFUDRE DSNURITD DSNURITC DSNTXAZP DSNDSPRM DSNURORG DSNURUIX DSNUGRAR DSNUGUTC DSNUGEPL DSNTIWMN DSNTIWMS DSNTIWAF DSNTIWIN DSNUGUCA DSNURBIB DSNURFUI DSNTINMF DSNDQWPZ DSNWZIFC DSNTIVMD DSNTIJUZ DSNTIVIA DSNURBXA DSNTIVIE DSNURBXE DSNURUIB DSNURUIA DSNURBXI DSN@XAZP DSNUGPRT DSN6SPRM DSNUGDDM DSNTIWPC DSNTIP63 DSNFUDIR DSNUIEPL DSNTIVMN DSNUGBPL DSNTIVAF DSNTIVIN DSNUMSGA DSNTIVMS DSNUMSGE
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RC10 PSY UI75477
UP21/05/26 P F105
Fix is available
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Document Information
Modified date:
14 October 2021